#include <ESP32Servo.h>

const int servoPin = 1;
int pos = 0;

Servo servo;

void setup() {
  servo.attach(servoPin);
}

void loop() {
    servo.write(pos);
    delay(1000);
    pos += 90;
    servo.write(pos);
    delay(1000);
    pos+=90;
    servo.write(pos);
    delay(1000);
    pos -= 90;
    servo.write(pos);
    delay(1000);
    pos -= 90;
    servo.write(pos);
  }